The invention generally relates to the field of tuning display mechanisms for a multiband pushbutton tunable receiver. More particularly the present invention relates to an improved tuning display mechanism for an AM-FM radio receiver in which manual actuation of a tuning pushbutton results in selectively displaying the proper longitudinally extending scale which corresponds to the waveband to which the pushbutton has been predesignated to by a cam assembly carried by the pushbutton.
Generally, radio tuning displays have simultaneously displayed scales for all of the frequency wavebands which the radio can be tuned to. This is undesireable since there is only a limited amount of available visual display space on the front face of the radio receiver. Thus if all of the tuning scales which correspond to each of the different wavebands which the radio can be tuned to must be simultaneously displayed, then the size of each of these scales must be minimized in order to fit all of these scales within the limited amount of available display space. In addition, if all of the tuning scales are simultaneously displayed, the radio operator may become confused as to what frequency band his radio is currently tuned to.
Some prior art radio receivers have provided a pivotal display mechanism in which different longitudinally extending scales are displayed in response to the rotary motion of a manually actuatable band selector switch. While these prior art receivers do maximize the use of the available space at the front of the receiver for tuning display purposes, they require that the band and tuning display selector be initially manually actuated. Subsequently, a separate manual actuation of a tuning device is required to tune the radio to a specific desired frequency in the selected band.
Some prior art radio tuning devices have provided manually actuatable tuning pushbuttons which upon manual actuation simultaneously select one of a plurality of wavebands and also select a predetermined frequency within the selected waveband. A U.S. Patent to Wolf et al., No. 3,247,728, which is assigned to the same assignee as the present invention illustrates one such device. However these devices in no way illustrate or suggest providing a tuning display which selectively visually displays only the longitudinally extending scale that corresponds to the selected waveband in response to manual actuation of the tuning pushbutton. No provision is made for such a selective display in these prior art devices and there is no teaching of how such a display could be constructed without interfering with the tuning of the radio which is controlled by the substantially uninhibited inward slidable motion of the tuning pushbutton.